# NTSB WPR13LA233: Schweizer G-164D, N83110, Butte City, CA, May 16, 2013 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: May 15, 2013, 19:00 local (May 16, 2013, 02:00 UTC) - Place: Butte City, CA - Coordinates: 39.45969, -121.929229 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=39.4597&lon=-121.9292&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Defining event: [Maneuvering-low-alt flying: Inflight upset](https://openairdocs.org/ntsb-events/271) - Highest injury: Minor injuries - Injuries: 1 minor - Status: Completed, report December 11, 2013 - Report: Approved by Office Director - NTSB office: Western Pacific Region - Parties: FAA Sacramento FSDO - NTSB case key (mKey): 86913 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR13LA233 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/86913/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=86913 - Page: https://openairdocs.org/ntsb/WPR13LA233 ## Probable cause The pilot's failure to maintain airplane control after an encounter with wake turbulence while maneuvering at low altitude. Contributing to the accident was the pilot’s fatigue due to extended hours of wakefulness and high workload. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Schweizer G-164D, 1 case](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=8059059), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) - [Alertness/Fatigue: fatigue due to work schedule](https://openairdocs.org/ntsb-findings/02013520): Personnel issues › Physical · Pilot (probable cause); cases with it: [Schweizer G-164D, 1 case](https://openairdocs.org/ntsb-findings/02013520/cases.md?model=8059059), [All aircraft, 25 cases](https://openairdocs.org/ntsb-findings/02013520/cases.md) - [Turbulence: wake turbulence](https://openairdocs.org/ntsb-findings/03032025): Environmental issues › Conditions/weather/phenomena · Ability to respond/compensate (probable cause); cases with it: [Schweizer G-164D, 1 case](https://openairdocs.org/ntsb-findings/03032025/cases.md?model=8059059), [All aircraft, 47 cases](https://openairdocs.org/ntsb-findings/03032025/cases.md) - [Performance/control parameters: lateral/bank control](https://openairdocs.org/ntsb-findings/01062023): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Schweizer G-164D, 1 case](https://openairdocs.org/ntsb-findings/01062023/cases.md?model=8059059), [All aircraft, 390 cases](https://openairdocs.org/ntsb-findings/01062023/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Maneuvering-low-alt flying: Low altitude operation/event](https://openairdocs.org/ntsb-events/220); cases with it: [Schweizer G-164D, 1 case](https://openairdocs.org/ntsb-events/220/sequence.md?model=8059059), [All aircraft, 780 cases](https://openairdocs.org/ntsb-events/220/sequence.md) - [Maneuvering-low-alt flying: Inflight upset](https://openairdocs.org/ntsb-events/271) (defining event); cases with it: [Schweizer G-164D, 1 case](https://openairdocs.org/ntsb-events/271/sequence.md?model=8059059), [All aircraft, 74 cases](https://openairdocs.org/ntsb-events/271/sequence.md) - [Maneuvering-low-alt flying: Loss of control in flight](https://openairdocs.org/ntsb-events/240); cases with it: [Schweizer G-164D, 1 case](https://openairdocs.org/ntsb-events/240/sequence.md?model=8059059), [All aircraft, 5,002 cases](https://openairdocs.org/ntsb-events/240/sequence.md) - [Maneuvering-low-alt flying: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Schweizer G-164D, 1 case](https://openairdocs.org/ntsb-events/470/sequence.md?model=8059059), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The pilot reported that he was at a low altitude and in a turn for the next agricultural aerial application run when the airplane encountered its wake turbulence, and the inside wing stalled. He tried to apply rudder to recover, but the airplane inverted and pitched nosedown before it impacted terrain. The pilot reported no preaccident mechanical malfunctions or failures with the airplane that would have precluded normal operation. The pilot awoke at 0445 on the day of the accident. He had been awake for over 15 hours and had flown 71 application loads during 12 of those hours at the time of the accident. Due to the early wake time and high work load, the pilot was most likely fatigued at the time of the accident. ## Factual narrative On May 15, 2013, about 1900 Pacific daylight time, a Schweizer Aircraft Corporation G-164D, N83110, collided with terrain near Butte City, California. Jones Flying Service, Inc., was operating the airplane under the provisions of 14 Code of Federal Regulations (CFR) Part 137. The commercial pilot sustained minor injuries; the airplane sustained substantial damage to the fuselage and wings from impact forces. The local aerial application flight departed Butte City at 1855. Visual meteorological (VMC) conditions prevailed, and no flight plan had been filed. The pilot reported that he was in a turn for the next application run. The airplane encountered its wake turbulence, and the inside wing stalled. It went inverted and pitched nose down. The pilot tried to correct with rudder application, but due to the low altitude he could not recover before the airplane contacted terrain. It came to rest in a rice field. The pilot was able to extricate himself, and walk to a road. The pilot stated that there were no mechanical malfunctions or failures with the airplane that would have precluded normal operation. The pilot had flown 12 hours and 71 loads on the day of the accident. He was awake at 0445 the morning of the accident, and characterized the day of flying as dawn to dusk; very busy with multiple loads. ## Aircraft - Registration: [N83110](https://openairdocs.org/aircraft/N83110), registered now, S/N 11D (OpenAirDocs) - Reported make and model: SCHWEIZER AIRCRAFT CORP G-164D - Registry model: [Schweizer G-164D](https://openairdocs.org/model/schweizer-g-164d) (registry code 8059059) (OpenAirDocs) - Registry engine: [Pratt & Whitney PT6A series](https://openairdocs.org/engine/pratt-whitney-pt6a-series) (registry code 52034, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 110 - Engines: P&W PT6-34AG 750 horsepower turbo prop - Damage: Substantial damage - Flight: Aerial application, Part 137 - Operator: JONES Flying Service, Inc - Registered owner: JONES Flying Service, Inc - Airworthiness certificate: Special, Restricted (Special) - Departed: Biggs, CA - Destination: Biggs, CA ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 45; injuries: minor; commercial; airplane ratings: single-engine land; medical: class 2, without waivers/limitations; last flight review October 24, 2012; seat: single; flight hours: 4,150 total, 2,200 in this make and model ## Weather - Conditions: Visual (VMC), Day - Wind: 140° at 7 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 79 °F, dew point 52 °F - Altimeter: 29.90 inHg - Observed at: KOVE ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Accident 20130515007799A](https://openairdocs.org/incident/20130515007799A), May 15, 2013: Schweizer Aircraft Corp G-164D, Biggs, CA, Destroyed. Pilot [privacy data omitted], narrative: While maneuvering for a swath I believe I crossed my wake causing a stall that inverted the airplane, thus impacting… ## Docket (1 files) The files NTSB released with the investigation on September 10, 2013, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=86913. 2.2 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 2.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40399357&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.